(a) Field of the invention:
The present invention relates to an electronic musical instrument, and more particularly it pertains to an electronic musical instrument capable of simulating natural sounds by a waveshape memory system.
(b) Description of the prior art:
Heretofore, many attempts have been made to electronically or electrically reproduce, by electronic musical instruments, natural sounds existing in the natural world and to produce arbitrary artificial sounds. For example, according to one proposed method, original sounds are recorded on magnetic tapes or the like and the recorded sound information is reproduced by mechanically driving the magnetic tapes selectively upon depressions of keys in an electronic musical instrument. Such method, therefore, is not purely electronic. Accordingly, it is difficult to quickly and faithfully follow up the depressions of keys which are performed at a high speed. Furthermore, in such a case, the rise and fall of a produced musical sound become very unnatural due to the mechanical nature of the tape feed.
There are many problems which are encountered in electronically synthesizing natural sounds. Generally speaking, a natural sound is formed of an extremely complicated combination of such factors as amplitude, frequency and phase. Moreover, all these factors vary with time. Therefore, it has been practically impossible to satisfy all such conditions, i.e. it has not been possible to reproduce all the complicated variations. Thus, the attempts to simulate natural sounds existing in the natural world have not succeeded at least in practice.